reactos/ntoskrnl/ex/zone.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/ex/zone.c
   5  * PURPOSE:         Implements zone buffers
   6  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
   7  *                  David Welch (welch@mcmail.com)
   8  */
   9
  10 /* INCLUDES ****************************************************************/
  11
  12 #include <ntoskrnl.h>
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 /* FUNCTIONS ***************************************************************/
  17
  18 /*
  19  * @implemented
  20  */
  21 NTSTATUS
  22 NTAPI
  23 ExExtendZone(PZONE_HEADER Zone,
  24              PVOID Segment,
  25              ULONG SegmentSize)
  26 {
  27     ULONG_PTR Entry;
  28     ULONG i;
  29
  30     /*
  31      * BlockSize and Segment must be 8-byte aligned.
  32      * Blocksize cannot exceed Segment Size.
  33      */
  34     if (((ULONG_PTR)Segment & 7) ||
  35         (SegmentSize & 7) ||
  36         (Zone->BlockSize > SegmentSize))
  37     {
  38         DPRINT1("Invalid ExExtendZone Alignment and/or Size\n");
  39         return STATUS_INVALID_PARAMETER;
  40     }
  41
  42     /* Link the Zone and Segment */
  43     PushEntryList(&Zone->SegmentList,
  44                   &((PZONE_SEGMENT_HEADER)Segment)->SegmentList);
  45
  46     /* Get to the first entry */
  47     Entry = (ULONG_PTR)Segment + sizeof(ZONE_SEGMENT_HEADER);
  48
  49     /* Loop through the segments */
  50     for (i = sizeof(ZONE_SEGMENT_HEADER);
  51          i <= SegmentSize - Zone->BlockSize;
  52          i+= Zone->BlockSize)
  53     {
  54         /* Link the Free and Segment Lists */
  55         PushEntryList(&Zone->FreeList, (PSINGLE_LIST_ENTRY)Entry);
  56
  57         /* Go to the next entry */
  58         Entry += Zone->BlockSize;
  59     }
  60
  61     /* Update Segment Size */
  62     Zone->TotalSegmentSize += i;
  63
  64     /* Return Success */
  65     return STATUS_SUCCESS;
  66 }
  67
  68 /*
  69  * @implemented
  70  */
  71 NTSTATUS
  72 NTAPI
  73 ExInterlockedExtendZone(PZONE_HEADER Zone,
  74                         PVOID Segment,
  75                         ULONG SegmentSize,
  76                         PKSPIN_LOCK Lock)
  77 {
  78     NTSTATUS Status;
  79     KIRQL OldIrql;
  80
  81     /* Get the lock */
  82     KeAcquireSpinLock(Lock, &OldIrql);
  83
  84     /* Extend the Zone */
  85     Status = ExExtendZone(Zone, Segment, SegmentSize);
  86
  87     /* Release lock and return status */
  88     KeReleaseSpinLock(Lock, OldIrql);
  89     return Status;
  90 }
  91
  92 /*
  93  * FUNCTION: Initializes a zone header
  94  * ARGUMENTS:
  95  *          Zone = zone header to be initialized
  96  *          BlockSize = Size (in bytes) of the allocation size of the zone
  97  *          InitialSegment = Initial segment of storage allocated by the
  98  *                           caller
  99  *          InitialSegmentSize = Initial size of the segment
 100  *
 101  * @implemented
 102  */
 103 NTSTATUS
 104 NTAPI
 105 ExInitializeZone(PZONE_HEADER Zone,
 106                  ULONG BlockSize,
 107                  PVOID InitialSegment,
 108                  ULONG InitialSegmentSize)
 109 {
 110     ULONG i;
 111     ULONG_PTR Entry;
 112
 113     /*
 114      * BlockSize and Segment must be 8-byte aligned.
 115      * Blocksize cannot exceed Segment Size.
 116      */
 117     if (((ULONG_PTR)InitialSegment & 7) ||
 118         (InitialSegmentSize & 7) ||
 119         (BlockSize > InitialSegmentSize))
 120     {
 121         DPRINT1("Invalid ExInitializeZone Alignment and/or Size\n");
 122         return STATUS_INVALID_PARAMETER;
 123     }
 124
 125     /* Set the Zone Header */
 126     Zone->BlockSize = BlockSize;
 127
 128     /* Link empty list */
 129     Zone->FreeList.Next = NULL;
 130     Zone->SegmentList.Next = NULL;
 131     PushEntryList(&Zone->SegmentList,
 132                   &((PZONE_SEGMENT_HEADER)InitialSegment)->SegmentList);
 133     ((PZONE_SEGMENT_HEADER)InitialSegment)->Reserved = NULL;
 134
 135     /* Get first entry */
 136     Entry = (ULONG_PTR)InitialSegment + sizeof(ZONE_SEGMENT_HEADER);
 137
 138     /* Loop through the segments */
 139     for (i = sizeof(ZONE_SEGMENT_HEADER);
 140          i <= InitialSegmentSize - BlockSize;
 141          i+= BlockSize)
 142     {
 143         /* Link the Free and Segment Lists */
 144         PushEntryList(&Zone->FreeList, (PSINGLE_LIST_ENTRY)Entry);
 145
 146         /* Go to the next entry */
 147         Entry += Zone->BlockSize;
 148     }
 149
 150     /* Set Segment Size */
 151     Zone->TotalSegmentSize = i;
 152
 153     /* Return success */
 154     return STATUS_SUCCESS;
 155 }
 156
 157 /* EOF */